全文获取类型
收费全文 | 4646篇 |
免费 | 299篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 156篇 |
妇产科学 | 133篇 |
基础医学 | 513篇 |
口腔科学 | 113篇 |
临床医学 | 559篇 |
内科学 | 821篇 |
皮肤病学 | 61篇 |
神经病学 | 325篇 |
特种医学 | 88篇 |
外科学 | 549篇 |
综合类 | 37篇 |
一般理论 | 5篇 |
预防医学 | 524篇 |
眼科学 | 72篇 |
药学 | 321篇 |
中国医学 | 7篇 |
肿瘤学 | 635篇 |
出版年
2023年 | 26篇 |
2022年 | 41篇 |
2021年 | 101篇 |
2020年 | 88篇 |
2019年 | 100篇 |
2018年 | 126篇 |
2017年 | 108篇 |
2016年 | 97篇 |
2015年 | 130篇 |
2014年 | 178篇 |
2013年 | 261篇 |
2012年 | 311篇 |
2011年 | 340篇 |
2010年 | 218篇 |
2009年 | 162篇 |
2008年 | 319篇 |
2007年 | 309篇 |
2006年 | 321篇 |
2005年 | 270篇 |
2004年 | 261篇 |
2003年 | 248篇 |
2002年 | 236篇 |
2001年 | 55篇 |
2000年 | 29篇 |
1999年 | 45篇 |
1998年 | 59篇 |
1997年 | 56篇 |
1996年 | 46篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 34篇 |
1992年 | 31篇 |
1991年 | 36篇 |
1990年 | 27篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1980年 | 17篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1968年 | 5篇 |
排序方式: 共有4961条查询结果,搜索用时 15 毫秒
61.
62.
Avoranta ST Korkeila EA Syrjänen KJ Pyrhönen SO Sundström JT 《World journal of gastroenterology : WJG》2012,18(33):4549-4556
AIM: To investigate the prognostic value of CD44 variant 6 (CD44v6), a membranous adhesion molecule, in rectal cancer.METHODS: Altogether, 210 rectal cancer samples from 214 patients treated with short-course radiotherapy (RT, n = 90), long-course (chemo) RT (n = 53) or surgery alone (n = 71) were studied with immunohistochemistry for CD44v6. The extent and intensity of membranous and cytoplasmic CD44v6 staining, and the intratumoral membranous staining pattern, were analyzed.RESULTS: Membranous CD44v6 expression was seen in 84% and cytoplasmic expression in 81% of the cases. In 59% of the tumors with membranous CD44v6 expression, the staining pattern in the invasive front was determined as “front-positive” and in 41% as “front-negative”. The latter pattern was associated with narrower circumferential margin (P = 0.01), infiltrative growth pattern (P < 0.001), and shorter disease-free survival in univariate survival analysis (P = 0.022) when compared to the “front-positive” tumors.CONCLUSION: The lack of membranous CD44v6 in the rectal cancer invasive front could be used as a method to identify patients at increased risk for recurrent disease. 相似文献
63.
64.
Erland Hermansen Gunnar Moen Johan Barstad Rune Birketvedt Kari Indrekvam 《European spine journal》2013,22(8):1913-1919
Introduction
Surgery for lumbar spinal stenosis (LSS) is today the most frequently performed procedure in the adult lumbar spine. Long-term benefit of surgery for LSS is well documented both in randomized and in non-randomized trials. In this paper, we present the results from laminarthrectomy as an alternative surgical approach, which have theoretical advantages over other approaches. In this study, we wanted to study the clinical and radiological results of laminarthrectomy. Dural sac cross-sectional areal (DSCSA) is an objective method to quantify the degree of central stenosis in the spinal canal, and was used to measure whether we were able to achieve an adequate decompression of the spinal canal with laminarthrectomy as a surgical approach.Materials and methods
All patients operated on with this approach consecutively in the period 1 January 2008 to 31 March 2009 were included in the study. All perioperative complications were noted. Clinical results were measured by means of a questionnaire. The patients that agreed to attend the study had an MRI taken of the operated level. DSCSA before and after surgery of the actual level were measured by three observers. We then performed a correlation test between increase of area and clinical results. We also tested for inter- and intra-observer reability.Results
Fifty-six laminarthrectomy were performed. There were 17 % complications, none of them were life-threatening or disabling. 46 patients attended the study and answered the questionnaire. Thirty-four patients (83 %) reported clinical improvement, whereas six (13 %) patients reported no improvement, and two (4 %) patients reported that they were worse. Mean ODI was 23.0. Mean EQ-5D was 0.77. Mean VAS-score for back-pain was 3.1 and mean VAS-score for leg-pain was 2.8. Mean DSCSA were measured to 80 mm2 before surgery and 161 mm2 after surgery. That gave an increase of DSCSA of 81 mm2 (101 %). We found a significant positive correlation between increase of area and clinical results. We also found consistent inter- and intra-observer reability.Discussion
In this study, the clinical results of laminarthrectomy were good, and comparable with other reports for LSS. The rates of complications are also comparable with other reports in spinal surgery. A significant increase in the spinal canal diameter was achieved. Within the limitations a retrospective study gives, we conclude that laminarthrectomy seems to be a safe and effective surgical approach for significant decompressing the adult central spinal canal, and measurement of DSCSA, before and after surgery seems to be a good way to quantify the degree of decompression. 相似文献65.
Kari Bø Gunvor Hilde Jette Stær Jensen Franziska Siafarikas Marie Ellstrøm Engh 《International urogynecology journal》2013,24(12):2065-2070
Introduction and hypothesis
Theoretically, tight or strong pelvic floor muscles may impair the progress of labor and lead to instrumental deliveries. We aimed to investigate whether vaginal resting pressure, pelvic floor muscle strength, or endurance at midpregnancy affect delivery outcome.Methods
This was a prospective cohort study of women giving birth at a university hospital. Vaginal resting pressure, pelvic floor muscle strength, and endurance in 300 nulliparous pregnant women were assessed at mean gestational week 20.8 (±1.4) using a high precision pressure transducer connected to a vaginal balloon. Delivery outcome measures [acute cesarean section, prolonged second stage of labor (> 2 h), instrumental vaginal delivery (vacuum and forceps), episiotomy, and third- and fourth-degree perineal tear) were retrieved from the hospital’s electronic birth records.Results
Twenty-three women were lost to follow-up, mostly because they gave birth at another hospital. Women with prolonged second stage had significantly higher resting pressure than women with second stage less than 2 h; the mean difference was 4.4 cmH2O [95 % confidence interval (CI) 1.2–7.6], p?<?0.01, adjusted odds ratio 1.049 (95 % CI 1.011–1.089, p?=?0.012). Vaginal resting pressure did not affect other delivery outcomes. Pelvic floor muscle strength and endurance similarly were not associated with any delivery outcomes.Conclusions
While midpregnancy vaginal resting pressure is associated with prolonged second stage of labor, neither vaginal resting pressure nor pelvic floor muscle strength or endurance are associated with operative delivery or perineal tears. Strong pelvic floor muscles are not disadvantageous for vaginal delivery. 相似文献66.
67.
68.
Jameela Abdulaziz Kari Sherif El-Desoky Youssef Farag Hisham Mosli Abdul-Malik Altyieb Ahmad Al Sayad Othman Radawi Hosam Ghabra Faten Basnawi Ohood Bahrawi Ajay Singh Hassan Farsi 《Pediatric nephrology (Berlin, Germany)》2013,28(6):927-931
Background
Posterior urethral valves (PUV) are a common cause of end-stage renal failure in childhood. Our aim was to describe a cohort of patients with PUV and to investigate the predictors of renal impairment.Methods
We performed a retrospective chart review of children with PUV who were followed at King Abdulaziz University hospital between 2002 and 2011.Results
The cohort comprised 68 boys. There was a significant difference in the duration of follow-up (p?=?0.024), nadir serum creatinine (p?<?0.001), and last known serum creatinine level (p?=?0.001) between the patients with and without renal impairment. The duration of follow-up appeared to be a significant predictor for serum creatinine doubling (p?=?0.003; odds ratio, 1.8). There was no difference in the age of presentation, age at the time of the study, and first or last serum creatinine between children who initially had vesicostomy and children who had ablation.Conclusions
Ablation of PUV or vesicostomy did not influence kidney function in our study cohort. Children with a normal nadir serum creatinine who presented early had a better outcome. 相似文献69.
Karin T. Beuker Synnve Schjølberg Kari Kveim Lie Rogier Donders Martijn Lappenschaar Sophie H. N. Swinkels Jan K. Buitelaar 《Journal of autism and developmental disorders》2013,43(1):45-56
It is unclear whether symptoms of autism spectrum disorder (ASD) in young children in the population fit the three-factor structure of ASD as described in the DSM-IV, and cluster together in individual subjects. This study analysed questionnaire data on ASD symptoms filled in by mothers of 11,332 18-month-old children that was collected in the context of the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health. Confirmatory Factor Analyses showed that the three-factor model had a significantly better fit then the two- and one-factor model of ASD symptoms. Latent class analysis revealed four homogeneous groups of children (classes) with different scores for Social Interaction and Communication at one hand and Stereotypies/Rigidity at the other hand. 相似文献